Friction Factor Equations Accuracy for Single and Two-Phase Flows

2020 ◽  
Author(s):  
Germano Scarabeli Custódio Assunção ◽  
Dykenlove Marcelin ◽  
João Carlos Von Hohendorff Filho ◽  
Denis José Schiozer ◽  
Marcelo Souza De Castro
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Computational Cost ◽  
Two Phase Flows ◽  
Two Phase ◽  
Explicit Equation ◽  
Implicit Equation ◽  
Lower Accuracy ◽  
Statistical Metrics

Abstract Estimate pressure drop throughout petroleum production and transport system has an important role to properly sizing the various parameters involved in those complex facilities. One of the most challenging variables used to calculate the pressure drop is the friction factor, also known as Darcy–Weisbach’s friction factor. In this context, Colebrook’ s equation is recognized by many engineers and scientists as the most accurate equation to estimate it. However, due to its computational cost, since it is an implicit equation, several explicit equations have been developed over the decades to accurately estimate friction factor in a straightforward way. This paper aims to investigate accuracy of 46 of those explicit equations and Colebrook implicit equation against 2397 experimental points from single-phase and two-phase flows, with Reynolds number between 3000 and 735000 and relative roughness between 0 and 1.40 × 10−3. Applying three different statistical metrics, we concluded that the best explicit equation, proposed by Achour et al. (2002), presented better accuracy to estimate friction factor than Colebrook’s equation. On the other hand, we also showed that equations developed by Wood (1966), Rao and Kumar (2007) and Brkić (2016) must be used in specifics conditions which were developed, otherwise can produce highly inaccurate results. The remaining equations presented good accuracy and can be applied, however, presented similar or lower accuracy than Colebrook’s equation.

Effects of Liquid Properties on Pressure Drop of Two-Phase Gas-Liquid Flows Through a Microchannel

2003 ◽  
Author(s):  
Akimaro Kawahara ◽  
Michio Sadatomi ◽  
Kazuya Okayama ◽  
Masahiro Kawaji
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Phase Flow ◽  
Distilled Water ◽  
Two Phase Flows ◽  
Two Phase ◽  
Factor Data ◽  
Flow Experiments ◽  
Working Liquid

Adiabatic experiments were conducted to measure pressure drop for single-phase liquid and gas-liquid two-phase flows through a circular microchannel with an internal diameter of 100 μm. In order to study the effects of liquid properties on the pressure drop, aqueous solutions of ethanol with different mass concentrations (4.8, 9.5, 49 and 100 wt%) in distilled water and distilled water were used as the working liquid, while nitrogen gas was used for the gas phase. The surface tension of the working liquid ranged from 0.023 N/m (100 wt% ethanol) to 0.072 N/m (water), and viscosity from 0.9 mPa·s (water) to 3.4 mPa·s (49 wt% ethanol aqueous solution). For the single-phase flow experiments, the friction factor data were obtained for each working liquid used, over a Reynolds number range of 2 < Re < 800. For the two-phase flow experiments, pressure drop data were collected over 0.2 < jG < 7 m/s for the superficial gas velocity and 0.1 < jL < 1 m/s for the superficial liquid velocity. For single-phase flows, friction factor data were shown to be in reasonable agreement with conventional theory. Furthermore, early transition from laminar to turbulent flow was not observed over the present experimental flow conditions. For two-phase flows, Lockhart & Martinelli’s correlation was found to be capable of predicting the present pressure drop data irrespective of the working liquid tested, if an appropriate constant needed in the correlation is adopted.

Pressure Drop for Single- and Two-Phase Flows Through a Return Bend in Horizontal Rectangular Microchannel and Minichannel

2015 ◽  
Author(s):  
Akimaro Kawahara ◽  
Michio Sadatomi ◽  
Shinichi Miyagawa ◽  
Mohamed H. Mansour
Keyword(s):  
Pressure Drop ◽  
Pressure Loss ◽  
Single Phase ◽  
Distribution Data ◽  
Micro Channel ◽  
Two Phase Flows ◽  
Two Phase ◽  
Rectangular Microchannel ◽  
Frictional Pressure Drop ◽  
Mini Channels

In this paper, single-phase liquid and two-phase gas-liquid pressure drop data through 180° return bends have been obtained for horizontal rectangular micro-channel and mini-channel. To investigate the size effects of the test channels, the hydraulic diameters were 0.25 mm and 3 mm respectively as the micro-channel and the mini-channel. The curvature radii of the bends were 0.500 mm and 0.875 mm for the micro-channel, while 6 mm for the mini-channel. To know liquid properties effects, distilled water, surfactant and glycerin aqueous solutions, ethanol and HFE (hydrofluoroether)-7200 were used as the test liquid, while nitrogen gas and air as the test gas. Pressure distributions upstream and downstream tangents of the bend were measured for the single-phase and the two-phase flows. From the pressure distribution data, the bend pressure loss was determined. By analyzing the present data, the bend loss coefficient for single-phase flow in both micro- and mini-channels could be correlated with Dean number. On the other side, the total bend pressure loss for two-phase flows were correlated by using an approach of Padilla et al., in which the total pressure loss is the sum of two pressure drop components, i.e., frictional pressure drop and singular pressure drop. The approach was found to be applicable to the present data for the micro- and the mini-channels if the frictional pressure drop was calculated by Lockhart-Martinelli method with Mishima & Hibiki’s correlation and Kawahara et al.’s correlation and the singular pressure drop was calculated by a newly developed empirical correlation.

Analysis of Friction Factor of Two-Phase Flow in Helically Coiled Tubes

2021 ◽  
Author(s):  
Baihui Jiang ◽  
Zhiwei Zhou ◽  
Yu Ji
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Steam Generators ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Applicable Range

Abstract With compact structure and enhanced heat transfer capacity, helical-coiled once through steam generators (HTSGs) are widely used in the small modular reactors (SMRs). Nevertheless, the inside centrifugal forces make the flow more complicated, and increase the frictional pressure drop, which is closely related to the dual test of alternating thermal stress and flow instability. Therefore, the analysis of the friction factor in helically coiled tubes is significant to the efficient and safe operation of HTSGs. While the friction factor of single-phase flow in helically coiled tubes was fully studied and extensive correlations have been validated by a large amount of experimental data, the friction factor of two-phase flow still lacks feasible prediction due to its much more complexity. The existed correlations of two-phase flow in helically coiled tubes are mostly based on specified experimental parameters, so the applicable range is limited. Few scholars have tried to extend these correlations to broader applicability, but the trivial applicable range is unsuitable for program development or engineering design, which needs an accurate prediction of friction factor in a wider range. In this paper, existing frictional pressure drop correlations are investigated. The accuracy of single-phase frictional pressure drop correlations is verified through the comparison of calculation results. Since the known experimental data cannot cover a wide range of parameters, two assumptions are proposed, and the rationality is verified through the existing experimental data and calculation analysis. Based on the two assumptions and calculation, a set of calculation correlations for frictional pressure drop of two-phase flow in helically coiled tubes are proposed. The accuracy of this calculation model is validated by experimental data. The scope of application of this model is: D / d = 15–100, P = 0.12–6.3MPa, G = 200–1500kg / m2s, which is sufficient to support the design and operation of steam generators and the development of the simulation programs.

Effects of Two-Phase Flow Friction Factor Correlations on the Optimal Pressure Drop-Martinelli Parameter Pair in a Mini-Channel

2016 ◽  
Vol 819 ◽  
pp. 309-313
Author(s):  
Normah Mohd Ghazali ◽  
Agus Sunjarianto Pamitran ◽  
Oh Jong-Taek ◽  
Robiah Ahmad ◽  
Muhammad Khairul Fitkry Rabin
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Homogeneous Model ◽  
Working Fluid ◽  
Two Phase Flows ◽  
Two Phase ◽  
Numerical Work ◽  
Frictional Pressure Drop ◽  
Mini Channels ◽  
The Many

Substantial research has been completed with more on-going on the flow pattern and heat transfer associated with two-phase flows. Discrepancies reported may have been as much as agreements, due to the different models, approaches, flow regimes, correlations, and new working fluids being utilized. This paper reports the outcome of a study to look at the effects of applying two different friction factor correlations on the simultaneous minimization of the pressure drop and Martinelli parameter under optimized flow rate and vapor quality, using genetic algorithm. The homogeneous model is assumed with ammonia as the working fluid, the coolant being environmentally friendly and having recently discovered as a potential replacement for the current refrigerants in micro and mini-channels. Results show that significant differences in the frictional pressure drop and Martinelli parameter arise due to the different correlations used, and this is only the outcome from two different correlations currently being considered by researchers in pressure drop analysis for two-phase flows in mini-channels. Thus, absolute agreement is indeed not possible between theoretical, experimental, and numerical work in view of the many different available correlations being utilized today with differences between 10 to 100 percent that has already been established.

Frictional pressure drop analysis for horizontal and vertical air-water two-phase flows in different pipe sizes

2018 ◽  
Vol 332 ◽  
pp. 147-161 ◽  
Author(s):  
Cihang Lu ◽  
Ran Kong ◽  
Shouxu Qiao ◽  
Joshua Larimer ◽  
Seungjin Kim ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop

Hydrodynamic and Thermal Performance of a Vapor-Venting Microchannel Copper Heat Exchanger

2008 ◽  
Author(s):  
Milnes P. David ◽  
Amy Marconnet ◽  
Kenneth E. Goodson
Keyword(s):  
Heat Exchanger ◽  
Carbon Fiber ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Heat Exchangers ◽  
Single Phase ◽  
Two Phase ◽  
Microchannel Heat Exchanger ◽  
Large Pressure ◽  
Dry Out

Two-phase microfluidic cooling has the potential to achieve low thermal resistances with relatively small pumping power requirements compared to single-phase heat exchanger technology. Two-phase cooling systems face practical challenges however, due to the instabilities, large pressure drop, and dry-out potential associated with the vapor phase. Our past work demonstrated that a novel vapor-venting membrane attached to a silicon microchannel heat exchanger can reduce the pressure drop for two-phase convection. This work develops two different types of vapor-venting copper heat exchangers with integrated hydrophobic PTFE membranes and attached thermocouples to quantify the thermal resistance and pressure-drop improvement over a non-venting control. The first type of heat exchanger, consisting of a PTFE phase separation membrane and a 170 micron thick carbon-fiber support membrane, shows no improvement in the thermal resistance and pressure drop. The results suggest that condensation and leakage into the carbon-fiber membrane suppresses venting and results in poor device performance. The second type of heat exchanger, which evacuates any liquid water on the vapor side of the PTFE membrane using 200 ml/min of air, reduces the thermal resistance by almost 35% in the single-phase regime in comparison. This work shows that water management, mechanical and surface properties of the membrane as well as its attachment and support within the heat exchanger are all key elements of the design of vapor-venting heat exchangers.

scholarly journals Experimental Investigation of Embedded Micropin-Fins for Single-Phase Heat Transfer and Pressure Drop

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Chirag R. Kharangate ◽  
Ki Wook Jung ◽  
Sangwoo Jung ◽  
Daeyoung Kong ◽  
Joseph Schaadt ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Friction Factor ◽  
Integrated Circuit ◽  
Single Phase ◽  
Absolute Error ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pin Fin

Three-dimensional (3D) stacked integrated circuit (IC) chips offer significant performance improvement, but offer important challenges for thermal management including, for the case of microfluidic cooling, constraints on channel dimensions, and pressure drop. Here, we investigate heat transfer and pressure drop characteristics of a microfluidic cooling device with staggered pin-fin array arrangement with dimensions as follows: diameter D = 46.5 μm; spacing, S ∼ 100 μm; and height, H ∼ 110 μm. Deionized single-phase water with mass flow rates of m˙ = 15.1–64.1 g/min was used as the working fluid, corresponding to values of Re (based on pin fin diameter) from 23 to 135, where heat fluxes up to 141 W/cm2 are removed. The measurements yield local Nusselt numbers that vary little along the heated channel length and values for both the Nu and the friction factor do not agree well with most data for pin fin geometries in the literature. Two new correlations for the average Nusselt number (∼Re1.04) and Fanning friction factor (∼Re−0.52) are proposed that capture the heat transfer and pressure drop behavior for the geometric and operating conditions tested in this study with mean absolute error (MAE) of 4.9% and 1.7%, respectively. The work shows that a more comprehensive investigation is required on thermofluidic characterization of pin fin arrays with channel heights Hf < 150 μm and fin spacing S = 50–500 μm, respectively, with the Reynolds number, Re < 300.

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